Nuclear Notes is produced by the Breakthrough Institute, and covers the policy, regulation, technology, and business of advanced nuclear energy in the United States and beyond.
Every Thursday, we track what’s really going on in the field: the new rules moving through the Nuclear Regulatory Commission, the advanced reactors moving from design to deployment, the companies going public and the utilities merging, and the executive orders and acts of Congress reshaping how the country builds. We explain not just what happened, but why it matters and how the pieces fit together.
A Boiling-Water SMR Gets a Construction Permit in Tennessee
The Nuclear Regulatory Commission has issued a construction permit to the Tennessee Valley Authority for a GE Vernova Hitachi BWRX-300, at a site called Clinch River, in Oak Ridge, Tennessee.
The TVA has been eager to build on the 935-acre site for years; in 2019 it became the first utility in the country to get pre-approval for a reactor there, without specifying what kind.
The NRC issued the permit very fast by nuclear standards, in 14 months, four months ahead of schedule, demonstrating increased efficiency at the agency. The license decision follows faster-than-expected action on several other applications.
One factor in fast action was using a pre-approved site, an approach that could speed up project development elsewhere.
“Clinch River is an important signal toward efficient reviews becoming routine rather than the exception,” said Adam Stein, Director of Nuclear Energy Innovation at the Breakthrough Institute, in a statement. “But predictability matters as much as speed,” he said. “Applicants need to know what information the NRC expects, when decisions will be made, and that the review will remain focused on what issues matter to public health and safety. The next challenge is making efficient licensing repeatable across a growing pipeline of various kinds of reactor applications.”
The construction permit has an odd distinction: It’s the first since the late 1970s issued to a utility, although utilities used to be the conventional party for building reactors. The agency has issued permits for research reactors to various institutions, and to two reactor developers: Kairos Power, for two salt-cooled high-temperature demonstration projects, Hermes 1 and 2, also in Oak Ridge; and TerraPower, in Kemmerer, Wyoming, for its Natrium fast reactor and energy storage system.
The NRC is also evaluating a construction permit application filed in March 2025 from X-energy, another non-utility, for a high-temperature gas-graphite reactor. The reactor, called Xe-100, would provide steam to a Dow chemical plant in Seadrift, Texas.
The Xe-100, Hermes, and Natrium are all Gen IV plants, moving beyond light-water into more innovative designs. But the BWRX set for Clinch River is based on a conventional Boiling Water Reactor (BWR) with the Roman numeral X added to designate it as tenth generation. Currently operating plants are known as Gen III, and the BWRX is Gen III+, incorporating passive safety systems. Emergency cooling is simplified by the reactor’s smaller size, 300 megawatts. The design also has some innovative construction techniques intended to reduce construction time and cost.
Among these construction techniques are “steel bricks,” which are composite structures that the plant will use in place of concrete in some locations. These bricks will substitute steel reinforcing bars in the concrete, cutting labor costs and construction time.
Because the BWRX is less of a technological leap than the Gen IV reactors, it may be poised for multiple additional orders from utilities that prefer refinements of already-tested technologies over exciting new concepts. GE Vernova-Hitachi says that 90 percent of the components of the BWRX are already in use in the nuclear industry. And the design has 80 percent less output than GE’s biggest design, with 90 percent less steel and concrete.
The BWRX-300 is also already under construction: Ontario Power Generation started work on a BWRX reactor in May 2025 at its Darlington site, on Lake Ontario, and has plans for three more. BWXT Canada, a subsidiary of the U.S. company of the same name, will build reactor vessels for the BWRX in Canada.
Numerous other customers are eyeing the BWRX-300. American Electric Power, Duke, and Sask Power are among potential customers. That reactor design also appears to be one of a handful of candidates for construction in New York, where the New York Power Authority has been told by the governor, Kathy Hochul, to build one gigawatt of new capacity using conventional technology.
The NRC, the TVA, Ontario Power Generation, the Canadian Nuclear Safety Commission, and GE Vernova-Hitachi have been cooperating closely with a goal of smoothing the licensing of the design in the United States. The president and chief executive of the TVA from April 2019 until April 2025 was Jeffrey Lyash, who was a former president and CEO of Ontario Power Generation.
The TVA has faced challenges getting to this point though. President Trump fired several members of the agency’s board last year, leaving it without a quorum from April until January of this year. Congress set a limit of $30 billion on the agency’s debt, and in its most recent report the agency counts a debt of $23.8 billion.
The projects in Darlington and Clinch River may be a chance to demonstrate the economics of small modular reactors, which reverse the old logic of reactor construction that big reactors had better economics. Ontario Power Generation is projecting a cost of about $7.7 billion (Canadian) or $5.4 billion (U.S.) for the first unit, which comes to $18,000 (U.S.) per kilowatt of capacity–a high number–with sharp reductions for subsequent projects.
Despite Proliferation Worries, a Saudi Deal Gets Some Backing
For nearly two decades, scholars and policymakers have warned about the risks of a civilian nuclear deal with Saudi Arabia. But that consensus may be changing. Among others, two researchers at Columbia University’s Center on Global Energy Policy have recently concluded that a Trump Administration deal to cooperate with the Kingdom of Saudi Arabia on civil nuclear projects would serve U.S. interests, despite the fact that it “has broken a decades-long U.S. nonproliferation taboo” because it does not include a prohibition on Saudi uranium enrichment.
Saudi Arabia says it wants nuclear reactors so it can reduce its use of fossil fuels, preserving more for export. It is also in informal competition with the United Arab Emirates, which has commissioned four large pressurized-water reactors of Korean design.
Notably, the UAE agreed not to enrich uranium and signed its 123 agreement in 2009 that has become known as the “gold standard,” under which it will import the fuel and export the spent fuel, which contains plutonium, although in a form that is difficult to use in weapons.
Saudi Arabia, in contrast, has historically refused to sign a deal that bars it from enrichment capabilities. The country has said it wants a nuclear program that includes not only reactors but fuel manufacturing. This has been the sticking point in the negotiations for years, especially since Crown Prince Mohammed bin Salman has stated publicly that Saudi Arabia would develop nuclear weapons if its neighbor Iran does. In September, Saudi Arabia announced that it had found 110 million metric tons of uranium-bearing ore.
But the Columbia researchers found that “the agreement contains several novel components that can help mitigate nonproliferation risks and offer significant benefits to U.S. national interests.” One is that Saudi Arabia will use “qualified suppliers” approved by the U.S. The agreement also calls for a lengthy study of enrichment, and bars centrifuge technology from being transferred to Saudi Arabia without additional negotiations. Another provision is a bilateral safeguards agreement.
The United States is eager to sell American-designed reactors to Saudi Arabia, specifically the Westinghouse AP1000. The consensus is that Saudi Arabia is likely just as eager for American technology and the additional areas of cooperation that come with signing such a deal with the U.S.
The Trump administration submitted the deal to Congress in August, and it will enter into force after 90 days of congressional session, unless both chambers object. But Congress cannot act before election day because the House has already ended its session, and time will be short in the lame duck session at the end of the year.
“Project Power” – $120 Billion Proposed for Eight New Nuclear Reactors
The United States and South Korea announced a framework for up to $120 billion in Korean investment to build eight large nuclear reactors in the United States: six Westinghouse AP1000s and two Korean-designed APR1400s. About $100 billion is earmarked for construction, with another $20 billion reserved for contingencies. Korea could also provide up to $10 billion by the end of this year, subject to legal approvals, to begin ordering long-lead equipment.
The APR1400 is already certified by the NRC, and Korea is eager to enter the U.S. market, with hardware or project management expertise. But such investment deals are announced more often than they are consummated; a year ago the Trump administration announced a deal for Japan to invest $80 billion in the U.S. nuclear sector, but the status of that program is unclear.
A Start-Up Seeks a License to Enrich Uranium
General Matter, a two-year-old California company, has applied to the NRC for permission to build an enrichment plant that it says will eventually make high-assay low-enriched uranium, or HALEU, the type that most advanced reactor designs require.
A year ago, the company announced that it had leased land from the Energy Department at Paducah: the site where the Atomic Energy Commission formerly used gaseous diffusion to enrich uranium. If built, it would be only the second American-owned enrichment plant. The United States imports most of enriched fuel, and some is produced at a European-owned plant in New Mexico. Plans for new reactors have exposed a shortage of enrichment capability, exacerbated by a decision to bar uranium enriched in Russia.
The company—which has backing from Peter Thiel and other investors—already has a $900 million contract from the Energy Department. The co-founder and CEO, Scott Nolan, was an early employee at SpaceX.
Nuclear Life Extension Has the Best Economics…
The Nuclear Energy Agency, part of the Organisation for Economic Co-operation and Development, and the Electric Power Research Institute, a non-profit utility consortium, have analyzed 23 different electricity- generating technologies in 21 countries, and concluded that extending generation at currently operating reactors would result in the least expensive cost of energy. Other contenders include large-scale reactors that are not the first of their kind to be built, solar photovoltaics (with or without batteries), and pumped hydro storage systems. But its annual survey observes that onshore wind and solar photovoltaic systems “remain attractive at the level of the individual plant, although compared to past editions, no significant further cost decreases have been observed.” And costs are higher “if their system costs are included.”
…And Increasing the Output of Older Reactors Works Well Too
Georgia Power announced that Google will spend about $900 million to expand the output of two of its nuclear facilities—Vogtle Electric Generating Plant Units 1 and 2, near Augusta, and Hatch Nuclear Power Plant, near Baxley—by a combined 96 megawatts.
The agreement, which is subject to the approval of the Georgia Public Service Commission, would add energy to the Georgia grid. Google would get clean energy credits, advancing its goal of reaching net zero carbon emissions by 2030.
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